Research On Key Technologies And Experimental For Difficult-to-Cut Materials Of Quasi-Intermittent Vibration-Assisted Cutting

Quasi-intermittent Vibration Assisted Swing Cutting(QVASC)is proposed on the basis of Elliptical Vibration Assisted Cutting(EVC),which aims to solve the problem of limited improvement in cutting accuracy due to residual height between adjacent trajectories,and its unique characteristics of intermittent cutting and cutting force homogenisation make it uniquely advantageous when cutting.This paper investigates the QVASC of difficult to machine materials.and the main research contents are as follows:(1)Briefly describe the principle of QVASC,and analyze the tool trajectory.And a 3D finite element simulation model of QVASC based on its actual machining state.The simulation process considers the QVASC tool contact conditions and subsequently analyses the change in cutting process forces by observing the simulation results and initially determining the range of cutting forces.(2)A cutting force modeling method combined with the machining characteristics of QVASC is proposed.Firstly,the QVASC cutting force prediction model is established,the process force is decomposed by the micro-element method,and parameters such as time-varying angle are introduced into the model.Then,the influence of various cutting parameters and tool parameters on the chip flow direction during QVASC machining is analyzed.Finally,the QVASC turning experiment was carried out.The KISTLER dynamometer(9019A)was used to observe and record the process force curve of silicon carbide,and to analyze the influence of various cutting parameters and tool parameters on the cutting force.(3)A critical undeformed chip thickness prediction model for brittle-plastic transition is established.A critical undeformed chip thickness prediction model was developed for SiC as the research object,based on the variation of cutting heat generated during machining,in order to investigate the influence of different process parameters on the brittle-plastic transformation of difficult-to-machine materials,and to summarise the preferred parameters of QVASC in machining difficult-to-machine materials such as SiC.(4)Experiments were carried out on variable cutting depth scribing of the difficult-to-machine material SiC.The target workpiece is grooved,and then the micro-grooves created by different cutting velocity and tool inclination angles are examined and analysed to reveal the chip formation mechanism of the above variables in the QVASC machining process.Combining the characteristics of brittle materials,an efficient and low-damage method for QVASC creation in hard and brittle materials is proposed.